今天看了一个例程,在nios2中用c实现一个电子钟. c是大概是这样的#include <stdio.h>
#include "system.h"
#include "altera_avalon_pio_regs.h"
#include <unistd.h>
#include "sys/alt_irq.h"
#include "alt_types.h"
#include "LCD.h"//自己设计的头文件
static volatile alt_u8 hour;
static volatile alt_u8 minute;
static volatile alt_u8 second;
static volatile alt_u16 year;
static volatile alt_u8 month;
static volatile alt_u8 day;
static volatile alt_u8 max_day;
static int flag;
static int begin;
static alt_u8 str1[17];
static alt_u8 str2[17];
volatile int edge_capture;
alt_u8 Tyear, Hyear, Dyear, Nyear;
static void last_day(){
if(month==4||month==5||month==9||month==11)
max_day=30;
else if(month==2){
if((year%4==0&&year%100!=0)||year%400==0)
max_day=29;
else
max_day=28;
}
else
max_day=31;
} static void handle_button_interrupts(void* context, alt_u32 id){
volatile int* edge_capture_ptr=(volatile int*)context;
*edge_capture_ptr=IORD_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE);
IOWR_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE,0);
} static void init_button_pio(){
void* edge_capture_ptr=(void*)&edge_capture;
IOWR_ALTERA_AVALON_PIO_IRQ_MASK(BUTTON_PIO_BASE,0xf);
IOWR_ALTERA_AVALON_PIO_EDGE_CAP(BUTTON_PIO_BASE,0x0);
alt_irq_register(BUTTON_PIO_IRQ,edge_capture_ptr,handle_button_interrupts);
}
void LCD_Init()//lcd初始化
{
lcd_write_cmd(LCD_DISPLAY_BASE,0x38); //lcd_write_cmd在头文件"LCD.h"中对应IOWR(base, 0, data)
usleep(2000);
lcd_write_cmd(LCD_DISPLAY_BASE,0x0C);
usleep(2000);
lcd_write_cmd(LCD_DISPLAY_BASE,0x01);
usleep(2000);
lcd_write_cmd(LCD_DISPLAY_BASE,0x06);
usleep(2000);
lcd_write_cmd(LCD_DISPLAY_BASE,0x80);
usleep(2000);
}
....... ....... static void handle_button_press(){
if(flag==0){
switch(edge_capture){
case 0x1:
timer_set();
display_time1();
usleep(500000);
display_time();
break;
case 0x2:
display_day();
break;
case 0x4:
display_time();
break;
default:
display_time();
break;
}
} ........ ........ int main()
{
init_button_pio();
LCD_Init();
initial_time();
while(1){
if(begin==0){
usleep(1000000);
second++;
if(second>=60){
second=0;
minute++;
}
if(minute>=60){
minute=0;
hour++;
}
if(hour>=24){
hour=0;
day++;
}
last_day();
if(day>max_day){
day=1;
month++;
last_day();
}
if(month>12){
day=1;
year++;
}
}
if(edge_capture!=0){
handle_button_press();
}
else{
if(flag==3||flag==4||flag==5||flag==6)
display_day();
else
display_time();
}
} 我想问一下:以上程序中标红色的那些字 1.(void LCD_Init中)应该是为了在对lcd初始化中实现某项功能吧?? 这些数对应的是什么功能呢?或者比如我自己要写程序时哪里能查到??我查了altra的几个文档都没有说明啊 2.(void handle_button_press中)应该是edge_capture在电路板上按下不同按键时捕获的值吧?? 哪里说明的那几个按键对应的是这几个数字?? 小弟初学,请帮帮忙 谢谢了!! | 
